The space shuttle Endeavour rolled from one Florida launch pad to another on Sunday in preparation for a complicated June construction flight to the International Space Station.

NASA parked Endeavour atop the seaside Launch Pad 39A at the Kennedy Space Center in Cape Canaveral., Fla., at 11:42 a.m. EDT after a more than eight-hour trek from its previous perch.

Endeavour is scheduled to blast off on June 13 to deliver a porch-like experiment platform to the space station that will complete the outpost's Japanese Kibo laboratory. Five spacewalks are planned for the marathon 16-day mission to install and outfit the new experiment porch and deliver vital spare parts.

NASA moved Endeavour to Pad 39A from the nearby Launch Pad 39B, where it had been on standby to fly a rescue mission for astronauts aboard its sister ship Atlantis in case an unexpected emergency occurred during their recent mission to overhaul the Hubble Space Telescope. No rescue was needed and Atlantis landed safely in California on May 24, but bad weather has delayed its ferry flight back atop a modified jumbo jet.

Launch pads 39A and 3B are only one mile apart from point to point, but NASA's massive Apollo-era crawler carrier vehicle had to haul the 100-ton Endeavour along a 3.4-mile path that links the two launch sites. It was only the fourth time in NASA's 28-year history of shuttle flight that a shuttle swapped launch pads.

Endeavour's move also marked the last time in history a shuttle was parked atop Pad 39B. NASA is converting the shuttle launch site to host its new Ares I rocket and Orion crew capsules. Substantial modifications are required before the first planned test flight, Ares I-X, no earlier than Aug. 30.

The cargo for Endeavour's mission was already at awaiting the orbiter's arrival at Pad 39A. It will be moved into the shuttle's 60-foot payload over the next week, NASA officials said.

Endeavour's seven-astronaut crew, commanded by veteran spaceflyer Mark Polansky, is due climb into the shuttle on Thursday during a launch dress rehearsal and an emergency escape drill.

The shuttle's STS-127 mission to the space station will mark NASA's third shuttle flight of five planned in 2009.

The 12 orbiting astronauts on the International Space Station were hailed by the chief on Thursday — and also got a humorous scolding for keeping their android crewmate locked up in its packing for so long.